Bumper systems typically extend widthwise, or transverse, across the front and rear of a vehicle and are mounted to rails that extend in a lengthwise direction. Many bumper assemblies for an automotive vehicle include a beam and an injection molded energy absorber secured to the beam. Assembly can further include a fascia for covering the beam and the energy absorber. The bumper assembly can further include a separately fabricated under tray, or spoiler, to prevent drag and under current beneath the car body. The under tray can also prevent debris from entering the under hood area.
Desirable energy absorbing bumper systems achieve high efficiency by building load quickly to just under the load limit of the rails and maintain that load constant until the impact energy has been dissipated. Currently, many vehicles, for example automotive vehicles, are designed with an upper and a lower energy absorber that are made to connect to the upper and lower beams, respectively. Upper and lower energy absorbers and bumper beams are commonly designed separately so that the lower energy absorber meets pedestrian impact and some vehicle safety requirements. The new legislation requires a level of pedestrian protection during impact with the front end of an automotive vehicle. The impact energy levels during such an occurrence are much lower than the traditional 5 mph vehicle bumper impacts. Legislation requirements include US FMVSS 5 miles per hour (mph) impact requirements, European ECE42 legislation, Allianz impact requirements and European and Asian Pedestrian Protection for lower and upper legs.
Traditional vehicle bumper systems and energy absorbers are designed to protect vehicle structures and/or occupants of the vehicle during low speed, about 5 miles per hour (mph), in a vehicle-to-vehicle or vehicle-to-solid structure impact. However, conventional bumper systems and energy absorbers are often too stiff to mitigate pedestrian injury, and/or are otherwise, highly complex having a large number of parts which can make them difficult and expensive to manufacture.